Rear Wheel bearings: NTN grease good, or repack?

[LeolaPA 12]

I was talking to a local Subaru repair shop the other day about installing a wheel bearing in the rear of our 95 Legacy wagon.  I bought a bearing from the local Subaru dealer, and it came with grease.  The local guy says that that grease is not good, and I should repack it before installing it with high pressure grease.  He claims that grease is just to keep it from corrosion.

 

That seems hard to believe for me.  I would think that a new bearing would come ready to install, and that the grease would be the proper type. 

 

Are there any Subaru techs that work for dealers who can give their opinion on this?

 

Thanks!

[moosens 510]

Would not hurt the cause if you followed his direction. Is the car Front Wheel Drive?

[el_freddo 719]

Always repack bearings from the shop.  As stated, the grease in there is simply packing grease.

 

Use a good quality high temp bearing grease and learn how to pack the grease into the bearing properly before installing into the vehicle.

 

Cheers

Bennie

[idosubaru 1910]

You and the shop may both be right, or well founded in your opinions.

 

I install OEM bearings without packing in new grease and have had no issues. If it wasn’t real grease I can’t imagine not noticing.

 

Someone more knowledgeable will chime in but I think it *used to be the case* that certain bearings did come with low end, if maybe packing, grease.

 

That I don’t think is the case now, but some still say you’re better off packing with a high quality grease.

 

It’s good to remember in general that simple one size fits all solutions fit shops better than individuals - all years, OEM, brands, models and particularly manufacturers...easier to just make sure than check each possible combination.

 

If you’re buying aftermarket bearings I would repack them. Subaru seems to lean towards better, though not always the best, fluid and grease choices than aftermarket as a whole.

.

[1 Lucky Texan 1022]

I have read of this controversy a coupla times in the past - seems to come up every 4-5 years.

[GeneralDisorder 1747]

Bearings that are shipped with corrosion protection only are lightly oiled and wrapped in special paper. 

 

Bearings that come with grease are intended to run that grease. 

 

Been installing Subaru wheel bearings from NTN and Koyo for 10+ years and NEVER had a repeat failure using the included grease. That's hundreds of bearings. 

 

Do as you like but you are only creating unnecessary work for yourself by cleaning and repacking them.

 

GD

[carfreak85 444]

Since we're on the topic of repacking wheel bearings, what is your preferred method of cleaning the original grease out of the bearings?

 

I've done this once so far to get a higher-temp grease in the bearings for my WRX, but it was pretty labor intensive.

[GeneralDisorder 1747]

Since we're on the topic of repacking wheel bearings, what is your preferred method of cleaning the original grease out of the bearings?

 

I've done this once so far to get a higher-temp grease in the bearings for my WRX, but it was pretty labor intensive.

 

What would lead you to believe this is even necessary? I work on cars that are tracked HARD on a regular basis. One of my customer's has an 06 WRX that is tracked every summer, all summer since new (he's retired and travels the entire west coast racing for his hobby) and he has 180k on his original bearings. He travels with three sets of tires - racing slicks, rain tires, and street tires. Races against Corvette, Audi's, and other high performance cars. His bearings have out lasted his original engine which blew a HG and had a cracked oil pickup tube. 

 

Not one single time have we ever had to replace wheel bearings or consider different grease due to temperature concerns. On ANY track car. This isn't even on the radar. 

 

GD

Edited March 8, 2018 by GeneralDisorder

[1 Lucky Texan 1022]

I would have thought track punishment/brake heat 'could' have compromised WB grease too. interesting.

 

I have an 06 WRX, I always felt that if I ever had a reason to drop the oil pan I'd get a killerB pick-up. I HATE driving around with a potential time bomb in there!

[GeneralDisorder 1747]

I have an 06 WRX, I always felt that if I ever had a reason to drop the oil pan I'd get a killerB pick-up. I HATE driving around with a potential time bomb in there!

You should do this ASAP. Every single failure I've seen has been on an '06.

 

It's not that hard of a job. Buy a new pan from Subaru and a Killer-B pickup. New pan is much easier than cleaning the old one.

 

GD

[1 Lucky Texan 1022]

yikes, maybe later this spring or summer - in the middle of moving house selling/buying/moving right now.

 

there's gonna be a tricky bolt/screw to reach IIRC?

 

how do you feel about a killer b pan? unnecessary and too expensive?

[GeneralDisorder 1747]

They are very nice. Definitely worth the price in my opinion. Extra 1.5 quart capacity and the new version is cast aluminium. Fitment is virtually perfect.

 

You need a wobbly 10mm 1/4" drive socket. Pull the intercooler, pitch stop, and jack the engine as far out of the cradle as you can.

 

If you want or need engine mount upgrades (we like Cusco but be warned they are pretty much full race mounts and you will get some vibration) thats the time to do them also.

 

GD

[1 Lucky Texan 1022]

thanx GD

 

sorry for the thread hijack Leola

[carfreak85 444]

GD, I don't know your customers, how their cars are set up, or if they're actually any good at driving or not.  It really doesn't matter how many sets of rubber they have, or what kind of cars they compete against, or anything else really.

 

First off, I'm talking about the 5x100 wheel bearings only.  5x114.3-equipped STIs got different, stronger wheel bearings.

 

Our WRX is a daily-driven car that, early in it's life, was used as an Auto-X toy by my father and I.  Two drivers per event, 6-10 laps per driver, 6-10 events per year for 5+ years.  The original wheel bearings started to fail around 120k miles.  One failed radially, one failed axially.  Stock suspension, wheels and brakes (SCCA D-stock rules), but with the stickiest summer tires we could afford.

 

When I looked into replacement bearing options I did a ton of research.  I suggest you do a google/NASIOC search for a guy called Gary Sheehan.  He was the driver who debuted the WRX in the USTCC back in 2002/2003.  His front wheel bearings were dying due to excessive brake heat conducting into the hubs, the bearings and was cooking the grease until the bearing physically failed.  The fix was multi-faceted, but essentially what the team did was:

 

• 2-piece brake rotors (Stoptech BBK, said this was the #1 thing to preserve bearing life)
• An older bearing part number that is now NLA, which had 8,000 lbs. more load capacity vs. the OEM bearing
• Repack the new bearings with a nylon-cage-compatible, high-temp grease (DuPont Krytox, NEO HP800, etc.)
• Over-torque the axle nut to 145 lb-ft. (As recommended to Sheehan's team by the lead tech at SOA)

 

Gary believes the bearing package is the weak point.  Heck, the conversation even drew in an engineer from NTN who gave us input for the alternate bearing part number and also advised on the proper grease to use that won't degrade the nylon bearing cage.

 

TL;DR - The 5x100 bearings DO have premature failures if in "extreme use" cases.

[GeneralDisorder 1747]

120k is not really a premature failure though. Even if they had to be done twice as often - not really enough of an issue to go out of the way to "correct" on a vehicle that is only seeing enough abuse to have a failure after 120k. If they were failing once a season I might consider some type of upgrade. Otherwise it's a waste of time for anything that isn't a full-on race car and isn't seeing regular failures. And if that's the case - upgrade to STI knuckles. 

 

If higher temps are being seen then simply changing the grease really isn't enough because the thermal growth will cause too much load inside the bearing assembly. At that point you need to loosen up the clearances with a spacer shim between the bearing cone's. Probably change the grease and the cage material as well. Or just get bigger brakes that don't get as hot. Air ducts to cool them also. 

 

GD

[idosubaru 1910]

I can see it either way. GD is right in that excessive bearing failure isn’t common enough to warrant exceptional replacement protocols.

 

The previous example even supports that. 120k in a well romped race use vehicle sounds really good for someone who’s just going to be daily driving a car.

 

But if someone were massively risk averse control tower employee types then sure have at it if you want that warm fuzzy of a “maybe”.

[Mike104 141]

Bearing quality and installation technique probably have more impact on bearing life than the grease.  Although since some Foresters seem to have more failures on the right rear bearing I did clean and repack that bearing with Lucas Red and Tacky, I don't know if that will have any effect but didn't think it would hurt anything.  I have only changed a handful of bearings on Subaru's so GD's experience with changing hundreds is certainly more valid.

[kamesama980 12]

Bearings that are shipped with corrosion protection only are lightly oiled and wrapped in special paper. 

 

Bearings that come with grease are intended to run that grease. 

 

Been installing Subaru wheel bearings from NTN and Koyo for 10+ years and NEVER had a repeat failure using the included grease. That's hundreds of bearings. 

 

Do as you like but you are only creating unnecessary work for yourself by cleaning and repacking them.

 

GD

^this! Have installed hundreds of wheel bearings of this style in the shop and a few of my own and no problems.

Besides there are enough idiots out there that the mfr wouldn't ship it in something that looks OK but isn't even if it were wrapped in warning labels. They'd be out of business from the lawsuits in about three seconds. That being said, the grease used is probably the bare minimum to get by without lawsuits and I see no fault with wanting something better.

 

I would have thought track punishment/brake heat 'could' have compromised WB grease too. interesting.

 

I have an 06 WRX, I always felt that if I ever had a reason to drop the oil pan I'd get a killerB pick-up. I HATE driving around with a potential time bomb in there!

 

It does but it takes a fair bit of heat input in a short span to all of the components in the area to get them hot enough. I would expect to fail the seals and lose the grease or have foreign material intrusion before the grease failed completely.

[LeolaPA 12]

I have read of this controversy a coupla times in the past - seems to come up every 4-5 years.

I'm just coming into this issue now and didn't know that.

[LeolaPA 12]

Bearings that are shipped with corrosion protection only are lightly oiled and wrapped in special paper. 

 

Bearings that come with grease are intended to run that grease. 

 

Been installing Subaru wheel bearings from NTN and Koyo for 10+ years and NEVER had a repeat failure using the included grease. That's hundreds of bearings. 

 

Do as you like but you are only creating unnecessary work for yourself by cleaning and repacking them.

 

GD

I bought NTN bearings from the Subaru dealer.  They were greased, not just oiled. 

 

By the way, I looked at a bunch of videos on Youtube, and one guy recommended putting the bearing  race onto the hub (outer seal, then the race) with a press and putting the outer race into the hub, then pulling them together.  What is your feeling on that? 

[LeolaPA 12]

Thanks to everybody for the comments!

[GeneralDisorder 1747]

I bought NTN bearings from the Subaru dealer. They were greased, not just oiled.

 

By the way, I looked at a bunch of videos on Youtube, and one guy recommended putting the bearing race onto the hub (outer seal, then the race) with a press and putting the outer race into the hub, then pulling them together. What is your feeling on that?

Definitely not! The seal must be installed in the knuckle to insure it is properly seated. The hub is pressed through the outer seal, and both bearing cones simultaneously.

 

GD

[LeolaPA 12]

Definitely not! The seal must be installed in the knuckle to insure it is properly seated. The hub is pressed through the outer seal, and both bearing cones simultaneously.

 

GD

They say that the fit of the outer seal is not as tight as some of the others and that it can go in that way....in other words, the seal can be pushed in with screw drivers after it's all together.  They say there is less tendency to damage the outer rollers, since that cone is pressed on using the steel race and not the rollers.  if you press the hub through both cones, the outer cone bearings have to take all the force as the hub is going through the outer part. 

[GeneralDisorder 1747]

I think they don't understand what's going on when you press the hub in. You support the inner cone/inner race, which pushes on the outer cone's inner race. No more force than is normally encountered when the bearing is fully assembled is put on the rollers as the clearances are set by the dimensions of the two inner races.

 

Sounds to me like they are doing it wrong, and then changed their approach to do it wrong another way instead of learning and understanding the right way to do it. 

 

I am doing it the way the factory service manual outlines using the SST made by Kent-Moore. Though I use a Hub Tamer by OTC. Same tool just different branding and 1/10th the price.  

 

GD

Edited March 19, 2018 by GeneralDisorder

[Gloyale 985]

I think they don't understand what's going on when you press the hub in. You support the inner cone/inner race, which pushes on the outer cone's inner race. No more force than is normally encountered when the bearing is fully assembled is put on the rollers as the clearances are set by the dimensions of the two inner races.

 

+1

 

FWIW, I use a slide hammer to pull the hubs and remove backing plate, and then I remove the knuckle and take it to a press for assembly.

 

Found hub tamer kits to be a crapshoot, and awkward.

 

I also repack all my bearings with High temp bearing grease.  Don't trust the quality or quantity of shipping grease.  

 

Just my $.02 and I know others disagree so I won't rehash in hear again.